Diet Might Help Prevent Cataracts

CHANCES are high that you'll develop a cataract after the age of 75. Up to seven out of eight people do. But new evidence suggests that your dietary choices can affect your cataract odds.

Harvard researchers made the finding in two large studies involving more than 110,000 men and women. Those people who ate the most foods rich in lutein and zeaxanthin (zee-a-ZAN-thin), two compounds related to beta-carotene, were significantly less likely to develop age-related cataracts than those who ate the least. Foods high in the two substances consist mostly of dark green leafy vegetables--namely spinach, broccoli, collard greens, kale, mustard greens, and winter squash as welt as corn and peppers. (Egg yolks have some, too.) Based on the results, at least three servings weekly of dark green vegetables appear protective.

The investigators suspect that lutein and zeaxanthin act as antioxidants in the eye, protecting cells in eye tissue from damage caused by sunlight. Earlier research has suggested that these same two substances may also play a role in warding off macular degeneration--the leading cause of irreversible blindness among older Americans. A multi-center study of more than 850 people conducted about 5 years ago showed that people who typically ate lutein- and zeaxanthin-rich greens two to four times a week were only about half as likely to end up with macular degeneration as people who ate them less than once a month.

Lutein and zeaxanthin are not the only substances in food thought to potentially impact eye health. A Tufts study conducted a couple of years ago indicated that vitamin C may prevent cataracts, too. In researching some 250 women in their 50s, 60s, and 70s, the Tufts scientists discovered that those who took in plenty of vitamin C had fewer cataracts than those who didn't.

The research may lead you to believe that taking so-called eye care supplements is a good idea, especially since pills containing lutein and other substances are now being heavily promoted. Don't bother. What we have at this point are associations between foods rich in certain nutrients and a reduced risk for eye problems, not cause-and-effect proof about particular compounds.

Some years ago, a lot of people started taking supplements of betacarotene when research suggested that foods rich in that nutrient reduced the risk for certain cancers. But when betacarotene itself was given to people in pill form in clinical trials, it increased cancer risk in certain groups.